IGF1-LR3

IGF-1 LR3 (Long R3 Insulin-Like Growth Factor-1) – Research Peptide

Modified 83-Amino-Acid IGF-1 Analogue for IGF-1 Receptor Signaling, Cell Growth, Protein Synthesis & Metabolic Research

IGF-1 LR3, also known as Long R3 IGF-1, Long-[Arg3]-IGF-I or LR3-IGF-1, is a modified analogue of human insulin-like growth factor-1 (IGF-1).

The molecule contains 83 amino acid residues and was engineered to investigate IGF-1 biological activity while reducing interactions with insulin-like growth factor-binding proteins (IGFBPs).

Native human IGF-1 contains 70 amino acids. IGF-1 LR3 differs from the natural hormone through two structural modifications:

• An additional 13-amino-acid sequence at the N-terminus.

• Replacement of glutamic acid with arginine at position 3 of the original IGF-1 sequence.

These changes substantially reduce binding to several IGF-binding proteins while preserving important IGF-1 receptor-associated biological activity.

IGF-1 LR3 has been investigated in research involving:

• IGF-1 receptor activation

• PI3K–AKT–mTOR signaling

• MAPK–ERK signaling

• Cellular growth and proliferation

• Protein synthesis-associated pathways

• Skeletal muscle cell biology

• Cell culture and bioprocess development

• IGF-binding protein interactions

• Glucose metabolism

• Cell survival and apoptosis

• Bone and cartilage physiology

• Growth factor pharmacology

The compound has also been used in mammalian cell culture research because its reduced binding to IGFBPs can alter the availability of growth factor activity in experimental systems.

Although IGF-1 LR3 has demonstrated biological activity in laboratory models, its clinical efficacy and safety in humans have not been established.

IGF-1 LR3 should not be confused with licensed recombinant human IGF-1 medicines, which contain a different molecular form.

ICAME Pharmacy IGF-1 LR3 is intended strictly for laboratory research and development purposes. Not for human or veterinary use.

What Is IGF-1 LR3?

IGF-1 LR3 is an engineered version of insulin-like growth factor-1.

IGF-1 is a naturally occurring peptide growth factor involved in growth, metabolism and cellular signaling.

It is produced by several tissues, including the liver, and its production is influenced by growth hormone (GH).

IGF-1 acts primarily through the type 1 insulin-like growth factor receptor (IGF1R).

This receptor regulates intracellular pathways associated with cell growth, survival and metabolism.

IGF-1 LR3 was developed to modify the interaction between IGF-1 and the proteins that normally regulate its availability.

These regulatory proteins are known as insulin-like growth factor-binding proteins, or IGFBPs.

The structural changes in IGF-1 LR3 reduce its affinity for IGFBPs in experimental systems.

As a result, the analogue can produce greater activity than native IGF-1 in certain cell-based assays.

However, greater activity in a laboratory assay does not establish superior clinical efficacy or safety.

IGF-1 LR3 Molecular Structure

IGF-1 LR3 is an 83-amino-acid polypeptide derived from human IGF-1.

Its molecular design combines a modified 70-amino-acid IGF-1 sequence with a 13-amino-acid N-terminal extension.

Molecular Characteristics

Compound Name: IGF-1 LR3

Full Name: Long R3 Insulin-Like Growth Factor-1

Alternative Names: Long-[Arg3]-IGF-I / LR3-IGF-1 / Long R3 IGF-I

Classification: Modified IGF-1 Analogue

Amino Acid Length: 83 Residues

Parent Molecule: Human IGF-1

Native IGF-1 Length: 70 Amino Acids

N-Terminal Extension: 13 Amino Acids

Key Substitution: Glutamic Acid to Arginine at Position 3 of the IGF-1 Portion

Approximate Molecular Weight: 9.1 kDa

Commonly Referenced CAS Number: 143045-27-6

Primary Receptor: IGF-1 Receptor (IGF1R)

Major Signaling Pathways: PI3K–AKT–mTOR / RAS–RAF–MEK–ERK

Primary Research Fields: Growth Factor Biology / Cell Culture / Receptor Signaling

Molecular specifications should be confirmed against the exact supplied sequence and analytical documentation.

Commercial materials may differ in purity, folding, salt form and formulation.

IGF-1 LR3 Amino Acid Sequence

The commonly described IGF-1 LR3 amino acid sequence is:

MFPAMPLSSLFVNGPRTLCGAELVDALQFVCGDRGFYFNKPTGYGSSSRRAPQTGIVDECCFRSCDLRRLEMYCAPLKPAKSA

This sequence contains 83 amino acids.

N-Terminal Extension

MFPAMPLSSLFVN

This 13-amino-acid extension is added before the modified IGF-1 sequence.

Arginine-3 Substitution

In native IGF-1, the third amino acid is glutamic acid.

In IGF-1 LR3, this position is occupied by arginine.

The substitution changes the physicochemical properties of the N-terminal region.

Why These Modifications Matter

The combination of the N-terminal extension and Arg3 substitution reduces the analogue's affinity for IGF-binding proteins.

This modification can increase receptor-accessible growth factor activity in certain experimental systems.

The molecule also contains three intramolecular disulfide bonds that contribute to its folded structure.

Correct folding is important for receptor interactions and biological activity.

Discovery and Development of IGF-1 LR3

The development of IGF-1 LR3 emerged from research into the relationship between IGF-1 structure, receptor binding and IGF-binding proteins.

Scientists investigated how changes in the IGF-1 amino acid sequence influenced its biological activity.

These studies identified regions important for interactions with IGFBPs.

Researchers subsequently developed modified IGF-1 analogues with altered binding properties.

Long R3 IGF-1 became particularly important because it retained IGF1R-associated activity while demonstrating markedly reduced binding to IGFBPs.

The analogue was subsequently investigated in mammalian cell culture and bioprocess research.

It has been used to study growth factor signaling and, in certain industrial systems, to support cell growth and recombinant protein production.

How Does IGF-1 LR3 Work?

IGF-1 LR3 acts primarily through the insulin-like growth factor-1 receptor (IGF1R).

IGF1R is a transmembrane receptor tyrosine kinase.

When activated by an appropriate ligand, the receptor undergoes autophosphorylation and initiates intracellular signaling.

Two major downstream signaling systems are:

PI3K–AKT–mTOR

and

RAS–RAF–MEK–ERK

These pathways participate in the regulation of cellular metabolism, growth, proliferation and survival.

Simplified Mechanism of Action

IGF-1 LR3

↓

IGF1R Binding

↓

Receptor Tyrosine Kinase Activation

↓

IRS / SHC-Associated Signaling

↓

PI3K–AKT–mTOR Pathway

and

RAS–RAF–MEK–ERK Pathway

↓

Experimental Changes in Cellular Growth, Metabolism and Survival Signaling

The biological outcome depends on the cell type, receptor expression, growth factor availability and experimental conditions.

IGF1R activation is not inherently beneficial in every context.

Growth-associated signaling can also contribute to unwanted cellular proliferation.

IGF-1 LR3 and the IGF-1 Receptor

The IGF-1 receptor is expressed in many tissues.

It belongs to the receptor tyrosine kinase family and is structurally related to the insulin receptor.

IGF1R participates in several cellular processes:

Cell growth

Cell proliferation

Cell survival

Metabolic regulation

Developmental signaling

Differentiation-associated pathways

IGF-1 LR3 is used experimentally to investigate how changes in ligand structure influence IGF1R-associated responses.

Its reduced binding to IGFBPs can be especially relevant in cell culture systems that produce binding proteins.

However, IGF1R activity must be interpreted in the context of other signaling pathways, including insulin receptor interactions.

IGF-1 LR3 and IGF-Binding Proteins (IGFBPs)

One of the defining characteristics of IGF-1 LR3 is its altered interaction with IGF-binding proteins.

The IGFBP family includes six classical high-affinity binding proteins:

IGFBP-1

IGFBP-2

IGFBP-3

IGFBP-4

IGFBP-5

IGFBP-6

These proteins influence the transport, distribution and availability of IGF ligands.

They can also modify growth factor activity in tissue-specific ways.

Native IGF-1

Native IGF-1 binds strongly to several IGFBPs.

This interaction can limit immediate receptor availability while also contributing to the regulation of IGF-1 distribution and persistence.

IGF-1 LR3

IGF-1 LR3 has substantially reduced affinity for IGFBPs in many experimental assays.

This can increase the proportion of growth factor available to interact with receptors in certain cell culture environments.

Important Distinction

Reduced IGFBP binding does not automatically mean a longer circulating half-life in humans.

Binding proteins can also protect native IGF-1 from clearance.

Consequently, pharmacokinetic behavior cannot be inferred solely from receptor potency or reduced IGFBP affinity.

IGF-1 LR3 and PI3K–AKT Signaling

The PI3K–AKT pathway is a major intracellular signaling system involved in cellular metabolism, growth and survival.

Following IGF1R activation, receptor-associated proteins can recruit PI3K.

PI3K-associated signaling contributes to AKT activation.

AKT regulates multiple downstream processes.

Research topics include:

Cell survival signaling

Glucose metabolism

Protein synthesis-associated regulation

Cellular growth

Apoptosis-associated pathways

Metabolic adaptation

IGF-1 LR3 can be used as a research ligand in systems investigating these mechanisms.

However, increased AKT phosphorylation is a biochemical observation, not proof of improved tissue function or clinical benefit.

IGF-1 LR3 and mTOR Research

Mechanistic target of rapamycin (mTOR) is a central regulator of cellular growth and nutrient-associated signaling.

The mTOR pathway integrates signals involving growth factors, energy availability and nutrient status.

IGF1R-associated PI3K–AKT signaling can influence mTOR activity.

Simplified Pathway

IGF-1 LR3

↓

IGF1R

↓

PI3K

↓

AKT

↓

mTORC1-Associated Regulation

↓

Protein Synthesis and Cellular Growth-Related Signaling

mTOR is involved in complex physiological processes.

Its activity is not universally beneficial, and prolonged or inappropriate growth signaling may contribute to disease-associated processes.

IGF-1 LR3 and MAPK–ERK Signaling

The MAPK–ERK pathway participates in cell proliferation, differentiation and responses to extracellular signals.

IGF1R activation can initiate signaling through adaptor proteins and the RAS–RAF–MEK–ERK cascade.

Relevant research endpoints include:

ERK phosphorylation

Cell-cycle-associated signaling

Growth factor responsiveness

Cell differentiation

Gene expression

Cell proliferation

These pathways are particularly relevant in developmental biology and cancer research.

The biological response depends on cell identity and the broader signaling environment.

IGF-1 LR3 and Cellular Growth Research

IGF-1 signaling is important in the regulation of cellular growth.

IGF-1 LR3 has been investigated as a growth factor analogue in laboratory systems.

Research has examined its influence on:

Cell proliferation

Cell survival

Growth factor responsiveness

Protein expression

Metabolic activity

Cellular differentiation

Some mammalian cell culture systems demonstrate enhanced growth-associated responses when exposed to IGF-1 LR3.

However, increased cellular proliferation is not automatically desirable.

Experimental outcomes must be evaluated according to the purpose of the research.

IGF-1 LR3 and Cell Culture Applications

IGF-1 LR3 has an established research history in mammalian cell culture.

Its reduced affinity for IGFBPs makes it useful for investigating growth factor activity in complex culture environments.

Relevant applications include:

• Mammalian cell growth research

• Growth factor receptor studies

• Cell survival assays

• Recombinant protein production research

• Serum-free culture development

• Cell metabolism research

• Bioprocess optimization

• Receptor phosphorylation studies

Certain industrial biotechnology applications have used Long R3 IGF-I as a growth factor component in cell culture media.

These applications are distinct from clinical use.

A reagent suitable for cell culture is not automatically suitable for administration to humans or animals.

IGF-1 LR3 and Recombinant Protein Production

Mammalian cell lines are widely used in biotechnology to manufacture recombinant proteins.

These systems require carefully controlled conditions to support cellular viability and productivity.

IGF-1 LR3 has been investigated in cell culture systems used for recombinant protein production.

Research topics include:

Cell growth

Cell viability

Protein expression

Culture productivity

Growth factor supplementation

Bioprocess consistency

The effect of IGF-1 LR3 depends on the specific cell line and culture environment.

It should not be assumed to increase productivity in every system.

IGF-1 LR3 and Skeletal Muscle Research

IGF-1 signaling participates in skeletal muscle development and maintenance.

The IGF1R pathway is involved in cellular processes associated with muscle growth and regeneration.

IGF-1 LR3 has been used in experimental systems investigating muscle cell biology.

Relevant research areas include:

Myoblast proliferation

Myogenic differentiation

Muscle protein signaling

AKT–mTOR activation

Cell survival

Muscle cell metabolism

Some cell and animal studies have reported growth-associated responses.

However, these findings do not establish that IGF-1 LR3 safely increases muscle mass or strength in humans.

Changes in molecular signaling are not equivalent to clinically meaningful muscle hypertrophy.

IGF-1 LR3 and Myoblast Research

Myoblasts are precursor cells involved in skeletal muscle development.

Their differentiation contributes to the formation of muscle fibers.

IGF-associated signaling influences myoblast proliferation and differentiation.

IGF-1 LR3 has been investigated in experimental models involving these processes.

Research endpoints include:

Cell proliferation

Myogenic marker expression

Cell differentiation

AKT signaling

ERK signaling

Protein synthesis-associated pathways

The balance between proliferation and differentiation depends on cellular conditions.

Greater growth factor activity does not necessarily improve all aspects of muscle development.

IGF-1 LR3 and Satellite Cell Biology

Skeletal muscle satellite cells are involved in muscle maintenance and repair.

These cells respond to local signals that influence activation, proliferation and differentiation.

IGF signaling is relevant to satellite cell research.

IGF-1 LR3 may be used as an experimental tool to investigate IGF-associated responses in appropriate models.

However, the direct effects of IGF-1 LR3 on human muscle regeneration remain insufficiently characterized.

The compound should not be marketed as a proven muscle recovery or injury treatment.

IGF-1 LR3 and Protein Synthesis Research

Protein synthesis is regulated by nutrient availability, cellular energy status and growth factor signaling.

IGF1R-associated pathways can influence components of the protein synthesis machinery.

Relevant research endpoints include:

AKT phosphorylation

mTOR-associated signaling

Ribosomal regulation

Protein turnover

Cellular growth

Growth factor responsiveness

IGF-1 LR3 is relevant to laboratory investigations of these mechanisms.

However, biochemical activation of protein synthesis-associated pathways does not establish improvements in human strength, athletic performance or recovery.

IGF-1 LR3 and Bone Research

IGF-1 plays an important role in skeletal development and bone physiology.

Its signaling influences osteoblasts, chondrocytes and other bone-related cell populations.

Research involving IGF-1 LR3 may examine:

Osteoblast signaling

Bone cell proliferation

Cartilage biology

Growth plate physiology

Extracellular matrix regulation

IGF1R-associated differentiation

However, findings from cell culture or animal models do not establish that IGF-1 LR3 improves bone density, fracture healing or skeletal health in humans.

IGF-1 LR3 and Cartilage Research

Cartilage contains specialized cells called chondrocytes.

These cells produce and maintain the extracellular matrix.

IGF-1 signaling participates in cartilage development and metabolism.

IGF-1 LR3 may be relevant to studies involving:

Chondrocyte proliferation

Cartilage matrix synthesis

Growth factor responsiveness

Developmental signaling

Cell survival

IGF receptor activation

Clinical efficacy for cartilage repair or joint disease has not been established.

IGF-1 LR3 and Metabolic Research

IGF-1 is structurally and functionally related to insulin.

Both hormones participate in metabolic regulation, although their receptors and physiological roles differ.

IGF-1 LR3 has been investigated in experimental metabolic systems.

Research topics include:

Glucose transport

Insulin-associated signaling

Cellular energy metabolism

Growth factor receptor interactions

Nutrient-responsive pathways

Metabolic adaptation

These studies do not establish IGF-1 LR3 as a treatment for diabetes, obesity or metabolic disorders.

IGF-1 LR3 and Glucose Metabolism

IGF-1 signaling can influence glucose utilization and insulin-associated pathways.

Because IGF-1 LR3 retains IGF receptor activity, glucose-related effects are an important safety consideration.

The IGF1R and insulin receptor share structural and signaling similarities.

Some experimental systems may also exhibit receptor cross-reactivity or hybrid receptor activity.

This makes interpretation of metabolic responses more complex.

Hypoglycemia Risk

IGF-related biological activity may lower blood glucose under certain conditions.

Severe hypoglycemia is a recognized risk of approved recombinant IGF-1 therapy.

Although the precise human risk profile of IGF-1 LR3 is not established, hypoglycemia is a significant theoretical and mechanistically plausible concern.

IGF-1 LR3 and Insulin Receptor Research

The insulin receptor and IGF-1 receptor belong to a related family of receptor tyrosine kinases.

Both can activate overlapping intracellular pathways.

However, their physiological roles and ligand affinities differ.

IGF-1 LR3 research may involve:

IGF1R activation

Insulin receptor cross-reactivity

Hybrid receptor signaling

AKT phosphorylation

Glucose-associated responses

Cell proliferation

Experimental interpretation should account for the expression of both receptor systems.

IGF-1 LR3 and Cell Survival

IGF-1 receptor signaling can influence pathways associated with cell survival.

AKT is an important mediator of several anti-apoptotic signaling responses.

IGF-1 LR3 has been investigated in experimental models involving cellular stress.

Relevant research topics include:

Apoptosis-associated proteins

AKT signaling

Cell viability

Stress responses

Growth factor deprivation

Cellular survival mechanisms

However, inhibition of apoptosis is not always desirable.

Programmed cell death is essential for removing damaged or potentially malignant cells.

IGF-1 LR3 and Cancer Biology

The IGF signaling system is important in cancer research.

IGF1R-associated pathways can influence cell proliferation, survival and resistance to apoptosis.

These mechanisms are relevant to the biology of certain tumors.

IGF-1 LR3 may be used as an experimental ligand to investigate:

Cancer cell growth

IGF1R activation

PI3K–AKT signaling

MAPK–ERK signaling

Cell survival

Growth factor dependence

Receptor-targeted experimental therapies

Important Safety Consideration

Because IGF-1 LR3 can activate growth-associated signaling, potential effects on abnormal cell proliferation must be considered.

Its long-term effects in humans are unknown.

It should not be assumed to be safe for individuals with active, previous or undiagnosed malignancy.

IGF-1 LR3 is not an established anticancer treatment.

IGF-1 LR3 and Aging Research

IGF-1 signaling is involved in biological processes associated with growth, metabolism and aging.

The relationship between IGF signaling and lifespan is complex.

Research in model organisms has demonstrated that altered insulin/IGF signaling can influence longevity-associated pathways.

However, these findings do not establish that increasing IGF-1 activity extends human lifespan.

IGF-1 LR3 has not been demonstrated to reverse biological aging.

It is not an established longevity treatment.

IGF-1 LR3 and Tissue Repair Research

IGF-1 signaling participates in cellular processes relevant to tissue growth and repair.

Researchers have investigated IGF-related pathways in experimental models involving:

Cell proliferation

Extracellular matrix biology

Muscle cell responses

Bone cell signaling

Connective tissue metabolism

Cell survival

However, the biological activity of native IGF-1 cannot automatically be attributed to IGF-1 LR3.

The modified analogue requires its own experimental evaluation.

Clinical efficacy for wound healing, injury recovery or tissue regeneration has not been established.

IGF-1 LR3 and Receptor Desensitization

Receptor responsiveness can change following prolonged stimulation.

Growth factor receptors are regulated through mechanisms that include internalization, recycling, degradation and feedback inhibition.

IGF1R signaling is subject to multiple regulatory processes.

Research involving IGF-1 LR3 may examine:

Receptor phosphorylation

Receptor internalization

Signal attenuation

Feedback regulation

Growth factor responsiveness

Cellular adaptation

However, the extent of receptor regulation depends on the model and exposure conditions.

No human administration strategy can be derived from these experimental observations.

IGF-1 LR3 and Protein Folding

IGF-1 LR3 contains multiple cysteine residues that form intramolecular disulfide bonds.

These bonds contribute to the molecule's three-dimensional structure.

Correct folding is important for receptor binding and biological activity.

Research has investigated the folding properties of Long-[Arg3]-IGF-I and compared them with native IGF-1.

Relevant research topics include:

Disulfide bond formation

Protein conformation

Folding intermediates

Structural stability

Receptor binding

Biological activity

A correct amino acid sequence does not guarantee that a research preparation is properly folded or biologically active.

IGF-1 LR3 vs. Native IGF-1

IGF-1 LR3 and native IGF-1 share a closely related molecular structure.

However, they are not identical.

The reduced IGFBP affinity of IGF-1 LR3 can increase activity in certain experimental assays.

It does not establish superior outcomes in humans.

IGF-1 LR3 vs. IGF-1 DES (1–3)

IGF-1 DES (1–3), also called Des(1–3) IGF-1, is another modified IGF-1 analogue.

It lacks the first three amino acid residues of native IGF-1.

IGF-1 LR3 instead contains an additional N-terminal sequence and an Arg3 substitution.

These compounds are distinct research molecules.

Their experimental effects should not be assumed to be identical.

IGF-1 LR3 vs. HGH 191AA

IGF-1 LR3 and HGH 191AA participate in related but different biological pathways.

HGH 191AA is the full-length human growth hormone protein.

IGF-1 LR3 is a modified analogue of IGF-1.

Comparison

The two molecules are not interchangeable.

IGF-1 LR3 vs. GHRP-6

GHRP-6 is a synthetic growth hormone secretagogue.

It activates GHS-R1a-associated signaling and stimulates endogenous GH secretion.

IGF-1 LR3 acts primarily through the IGF-1 receptor.

GHRP-6 acts upstream in the endocrine axis, while IGF-1 LR3 directly engages IGF-associated cellular signaling.

Their molecular structures, receptor targets and research applications differ.

IGF-1 LR3 vs. CJC-1295

CJC-1295 is a modified growth hormone-releasing hormone analogue.

It activates the GHRH receptor and stimulates endogenous GH secretion.

IGF-1 LR3 activates IGF1R-associated pathways.

Research involving different pathways does not establish the safety of combining experimental compounds.

IGF-1 LR3 and Human Clinical Evidence

IGF-1 LR3 has been studied primarily in laboratory and animal models.

Its research history includes investigations of:

IGFBP binding

Receptor activation

Cellular proliferation

Cell culture productivity

Protein folding

Growth-associated signaling

Animal physiology

However, published evidence does not establish clinical efficacy or an adequately characterized safety profile for IGF-1 LR3 in humans.

Important Distinction

Clinical trials involving native recombinant IGF-1 cannot be treated as clinical trials of IGF-1 LR3.

The structural modifications of IGF-1 LR3 affect its pharmacological properties.

Consequently, human safety, pharmacokinetics and efficacy cannot be assumed from the evidence for native IGF-1.

IGF-1 LR3 and Approved IGF-1 Medicines

Mecasermin is a recombinant human IGF-1 medicine used for selected medical indications.

It contains the native human IGF-1 amino acid sequence.

IGF-1 LR3 is structurally different.

It contains an N-terminal extension and an amino acid substitution.

Therefore, IGF-1 LR3 should not be presented as an equivalent or substitute for mecasermin.

The clinical evidence, regulatory approval and pharmaceutical quality controls associated with authorized mecasermin products do not automatically apply to IGF-1 LR3.

Potential Safety Concerns

IGF-1 LR3 is a biologically active growth factor analogue.

Its safety profile in humans has not been adequately established.

Important scientific concerns include:

Hypoglycemia

IGF-associated signaling can influence glucose regulation. Hypoglycemia is a significant concern, although the specific human risk associated with IGF-1 LR3 has not been quantified.

Cell Proliferation

IGF1R activation can stimulate growth-associated pathways.

Cancer-Related Concerns

IGF signaling is relevant to tumor biology. The consequences of prolonged IGF-1 LR3 exposure in humans are unknown.

Endocrine Interactions

The compound may influence signaling systems related to insulin and IGF regulation.

Receptor Cross-Reactivity

IGF and insulin receptor systems share structural and functional characteristics.

Protein Immunogenicity

Unverified protein preparations may introduce risks associated with impurities, aggregation or immune responses.

Unknown Pharmacokinetics

Human absorption, distribution, clearance and duration of action have not been adequately established.

Product Quality

Research-grade preparations may differ in identity, folding, purity, potency and impurity profile.

Long-Term Safety

Long-term systemic safety is unknown.

No research-grade IGF-1 LR3 preparation should be assumed suitable for human administration.

IGF-1 LR3 and Anti-Doping Regulations

IGF-1 and its analogues are prohibited under the World Anti-Doping Agency (WADA) framework.

IGF-1 LR3 falls within the category of IGF-1 analogues relevant to anti-doping regulations.

These substances are prohibited in sport.

A research-use designation does not provide an exemption from anti-doping rules.

Athletes and sports organizations should consult the current WADA Prohibited List and applicable regulations.

Scientific Evidence and Research Limitations

IGF-1 LR3 has a documented experimental research history.

However, its evidence base should be interpreted carefully.

Established Scientific Findings

• IGF-1 LR3 is an 83-amino-acid analogue of IGF-1.

• It contains a 13-amino-acid N-terminal extension.

• It includes an arginine substitution at position 3 of the IGF-1 portion.

• Its affinity for IGF-binding proteins is substantially reduced.

• It retains IGF1R-associated biological activity.

• It has been investigated in cell culture and growth factor signaling studies.

• Its structural properties and folding have been examined experimentally.

• It has applications in certain mammalian cell culture systems.

Important Limitations

• Human clinical efficacy has not been established.

• Human pharmacokinetics are insufficiently characterized.

• Long-term safety is unknown.

• Muscle-building benefits in humans are unproven.

• Fat-loss benefits in humans are unproven.

• Tissue regeneration benefits in humans are unproven.

• Anti-aging benefits are unsupported.

• Reduced IGFBP affinity does not prove prolonged human circulation.

• Experimental cell growth does not guarantee improved physiological function.

• IGF1R activation raises important questions about abnormal cell proliferation.

• Research-grade IGF-1 LR3 is not equivalent to licensed IGF-1 medicine.

Potential Research Applications

IGF-1 LR3 may be relevant to appropriately controlled scientific investigations involving:

• IGF-1 receptor pharmacology

• IGF-binding protein interactions

• PI3K–AKT signaling

• mTOR-associated pathways

• MAPK–ERK signaling

• Growth factor receptor phosphorylation

• Cell proliferation

• Cell survival

• Myoblast biology

• Skeletal muscle cell research

• Protein synthesis-associated signaling

• Bone cell biology

• Cartilage research

• Glucose metabolism

• Insulin receptor interactions

• Cellular differentiation

• Cancer signaling research

• Recombinant protein production

• Mammalian cell culture

• Serum-free media research

• Protein folding

• Disulfide bond formation

• Peptide structure–activity relationships

• Growth factor bioavailability

These are scientific research applications rather than established therapeutic benefits.

IGF-1 LR3 Research Overview

Compound Name: IGF-1 LR3

Full Name: Long R3 Insulin-Like Growth Factor-1

Alternative Names: Long-[Arg3]-IGF-I / LR3-IGF-1

Classification: Modified IGF-1 Analogue

Amino Acid Length: 83

Parent Molecule: Human IGF-1

N-Terminal Extension: 13 Amino Acids

Key Substitution: Glu3 → Arg

Approximate Molecular Weight: 9.1 kDa

Common CAS Number: 143045-27-6

Primary Receptor: IGF1R

Principal Signaling: PI3K–AKT–mTOR / MAPK–ERK

Main Research Fields: Cell Growth / IGFBP Biology / Growth Factor Signaling

Established Human Clinical Efficacy: None

Intended Product Use: Laboratory Research Only

Anti-Doping Status: Prohibited under WADA rules

Product Information

Product Name: IGF-1 LR3

Alternative Name: Long R3 IGF-1

Brand: ICAME Pharmacy

Product Category: Research Peptide / Growth Factor Analogue

Research Classification: Modified Insulin-Like Growth Factor-1

Research Areas: IGF1R / IGFBPs / PI3K–AKT / MAPK–ERK / Cell Culture

Intended Use: Laboratory Research & Development Only

The exact identity and specifications of the supplied material should be confirmed through manufacturer documentation.

Relevant batch-specific information includes:

• Verified amino acid sequence

• Molecular identity

• Protein folding

• Disulfide bond integrity

• Analytical purity

• Biological activity

• Impurity profile

• Certificate of Analysis (COA)

• Batch/lot identification

• Validated storage conditions

No claims of pharmaceutical quality, sterility, injectable suitability or clinical efficacy should be made without appropriate supporting documentation and regulatory authorization.

Important Research Use Notice

FOR RESEARCH USE ONLY (RUO)

This ICAME Pharmacy product is intended exclusively for legitimate laboratory, analytical and scientific research purposes.

Not for human or veterinary use. Not for diagnostic, therapeutic, bodybuilding, performance-enhancing, anti-aging, weight-loss or other clinical purposes. Not for direct administration to humans or animals.

IGF-1 LR3 is a biologically active growth factor analogue.

It can activate signaling pathways associated with cellular growth, metabolism and survival.

Human clinical efficacy and long-term systemic safety have not been established.

Potential risks include effects on glucose regulation and growth-associated cellular pathways.

IGF-1 LR3 is not equivalent to licensed recombinant human IGF-1 medicines.

Information presented on this page is intended solely for scientific and educational purposes and does not constitute medical advice, prescribing information, dosage guidance or instructions for human use.

About ICAME Pharmacy

ICAME Pharmacy provides specialized research products for professional laboratory and scientific applications.

Our portfolio focuses on compounds relevant to peptide science, growth factor biology, endocrinology, molecular signaling, cell culture and experimental pharmacology.

We emphasize accurate product identification, responsible research use, scientific transparency and clear communication of evidence limitations.

For batch-specific analytical documentation and product inquiries, please contact ICAME Pharmacy.

Frequently Asked Questions About IGF-1 LR3

What is IGF-1 LR3?

IGF-1 LR3 is an 83-amino-acid analogue of human IGF-1 developed to modify interactions with IGF-binding proteins while retaining IGF1R-associated activity.

What does LR3 mean?

LR3 refers to the long N-terminal extension and the arginine substitution at position 3 of the IGF-1 sequence.

How many amino acids does IGF-1 LR3 contain?

IGF-1 LR3 contains 83 amino acids.

What is the molecular weight of IGF-1 LR3?

Its approximate molecular weight is 9.1 kDa.

What receptor does IGF-1 LR3 activate?

Its principal target is the insulin-like growth factor-1 receptor, IGF1R.

What is the main mechanism of IGF-1 LR3?

IGF-1 LR3 activates IGF1R-associated signaling, including PI3K–AKT–mTOR and MAPK–ERK pathways.

How does IGF-1 LR3 differ from native IGF-1?

IGF-1 LR3 contains an additional 13 amino acids and an arginine substitution at position 3, resulting in reduced affinity for IGF-binding proteins.

Does IGF-1 LR3 have a longer half-life than IGF-1?

Reduced IGFBP binding does not automatically establish a longer circulating half-life. Human pharmacokinetic data are insufficient to confirm such a claim.

Does IGF-1 LR3 increase muscle growth?

It has been investigated in muscle-related experimental models, but clinically meaningful muscle growth in humans has not been established.

Is IGF-1 LR3 the same as HGH?

No. HGH is growth hormone, while IGF-1 LR3 is a modified IGF-1 analogue acting primarily through IGF1R.

Is IGF-1 LR3 the same as mecasermin?

No. Mecasermin contains recombinant native human IGF-1. IGF-1 LR3 has a different amino acid sequence.

Is IGF-1 LR3 approved for human treatment?

IGF-1 LR3 is not an established approved human therapeutic agent.

Is IGF-1 LR3 prohibited in sport?

Yes. IGF-1 analogues are prohibited under WADA anti-doping regulations.

Is ICAME Pharmacy IGF-1 LR3 intended for human use?

No. ICAME Pharmacy IGF-1 LR3 is intended strictly for laboratory research and development purposes.